Fig.1 Shows The enzyme–substrate complex and the active site
Enzymes have been long used in industrial processes. The use of enzymes in food manufacture dates back thousands of years. The making of cheese, vinegar, wine, bread and beer all rely on the use of enzymes. The biggest advantage in using enzymes in food manufacture and all other commercial processes is that they do not need high energy expenditures. This is because that enzymes operate at relatively low temperatures which are usually around 40°C.
The enzyme Pectinase is used in the fruit juice industry. Pectin is a polysaccharide that is present in and between plant cells. It causes cell walls to stick to adjacent cells during storage of fruit pulp and can bind water strongly so that it cannot be recovered. Pectinase is actually a group of enzymes that break down various structural components of pectin. Industries use pectinase to help clarify the juice of apples, cranberries and grape juice. It is also used in vinegar and wine making. Pectinase increases juice yields from cells by breaking down the pectin holding the juice in. It helps to make the juice, wine or vinegar clearer by breaking down the bits of cell that cause the juice to go cloudy. In this case, pectinase is mixed with cellulase. In the citrus industry it is used in the peeling process and to increase the yields of juice recovered. Pectin also sets jams and jellies. Pectinase is needed in fruit juices when they are concentrated to stop the juice from jelling. Pectinase acts optimally at around 35°C and at a pH of 5.5. It is obtained commercially from fungi particularly Aspergillus and Penicillium.
Proteases are also commercial enzymes. They hydrolyse peptides in proteins and polypeptides. Pepsins are endopeptidases. This means they break bonds in the middle of the polypeptide chain. Exopeptidases remove individual amino acids from the ends of polypeptides. Optimum temperature is 45ºC and pH 6.5. Proteases are used for cheese-making as a substitute for rennet to clarify fruit juice and beer by removing suspended protein to thin egg white for filtration before drying to tenderise meat and to modify proteins in flour which is used to make dough.
Lactase is also used commercially. It breaks down lactose to galactose and glucose. The optimal temperature is 48ºC and pH 6.5. It can break down lactose in milk produced for lactose-intolerant people .These people suffer nausea, abdominal pains, bloating and diarrhoea if lactose is not broken down because it is fermented by bacteria in the large intestine. It sweetens ice-cream and other milk products. It Degrades lactose which crystallises when ice-cream freezes.
Another commercial enzyme is Cellulase. Cellulose is broken into shorter chains by cellulase first into cellobiose and then into glucose. Cellulase is used to produce more sugars in beer by breaking cellulose into glucose that is turned into alcohol by enzymes in yeast. It is also used to clarify orange, lemon juice and beer and improve colour release from fruit skins by breaking down cell walls to release chromoplasts. It is used to tenderise green beans by breaking down the cellulose cell walls.It degrades paper, which is cellulose, in old newspapers, sawdust and straw. These sugars can then be turned into alcohol. This process is called saccharification.
Amylase is also an important commercial enzyme. It hydrolyses starch and glycogen, converting it to dextrin or maltose. It is stable over a wider range of temperatures than many other enzymes. The optimum pH is 4. It is used to clarify fruit juices, wines, beer, by removing starch. It is also used in bread-making and brewing; amylase creates sugars from starch and allows for a browner crust in bread. It converts starch to glucose syrup which is used in the food industry as a sweetener. Maltose is used in jam and confectionery and can also be converted into glucose, then further by the enzyme glucose isomerase, into fructose. This is what diabetics use in place of sucrose and glucose.
We can clearly see that enzymes are very important in the commercial world as they have a number of uses. They provide very good business sense as they do not require large amounts to run. Mainly due to the fact that they do not require high temperatures.
